Definite sarcasm.
A QB can definitely make a o-line look better or worse than it is, but you're exaggerating when you say it "doesn't matter." Like, for instance, my own team. For some reason due to low sack totals, our o-line was rated quite high last season and the past few as well. But if you watch the games, you'd see there is no way that this o-line is top 10, let alone top 3, as they're named by some morons occasionally. One of the only things that Andy Dalton does well is he has a retardedly quick release, and he gets rid of the ball faster than most QBs in the league. Makes the o-line look better than they are.
But using just sack totals when evaluating o-lines is kinda bullshyt, especially when dealing with a retarded QB who is unable to sense pressure or get rid of the ball when need be.
A GREAT HOF QB like Manning or Rodgers can over come a meh line, no shyt. They're all time greats. But most QBs in the league aren't all time greats.